<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            border-style: solid;
            border-color: gray;
            position: absolute;
            left: 600px;
            top: auto;
            transition: all 2s ease-in 0s;
        }

        div:hover {
            border-radius: 50%;
            box-shadow: inset 10px 10px 50px 20px gray;
        }
    </style>
</head>
<body>
<div></div>
</body>
</html>